Hello,i just purchased a used BAT VK 3i preamplifier from an Audio dealer in California. it uses four 6922 twin triode tubes which i am familiar with. the VK 3i also uses a pair of 6V6 tubes which i am unfamiliar with. i have a quad of Amperex 7308s with the green globe label that i intend to install when i receive this preamp which is due to arrive here early next week. does anyone have an opinion on which type or brand of 6V6 i should use ? does it matter or are all of them the same when it comes to sonics or reliability. thanks in advance for any replies or opinions...WCW III